ErbB receptors and PKC regulate PC12 neuronal-like differentiation and sodium current elicitation

Excitability, neurite outgrowth and their specification are very important features in the establishment of neuronal differentiation. We have studied a conditioned medium (CM) from sciatic nerve which is able to induce a neuronal-like differentiation of PC12 cells. Previously, we have demonstrated that supplementing this CM with a generic inhibitor (k252a), which mainly inhibits tropomyosin-related kinase receptors (Trk receptors) and protein kinase C (PKC), caused neurite elongation, sodium current induction and axon development. In the present work, we are showing that the enhancement of neurite length and induction of sodium currents induced by CM+k252a were prevented by ErbB receptor inhibition. Additionally, we demonstrated that specific inhibition of PKC produced a similar effect to that exerted by k252a in CM-treated cells, specifically by increasing the percentage of differentiated cells with long neurites and inducing sodium currents. Moreover, CM changed the mRNA levels for ErbB2 and ErbB3 increasing them 6- and 36-folds respectively compared to their control. The inclusion of k252a with CM changed the ErbB1, ErbB2 and ErbB3 mRNA proportions increasing those eight-, seven- and fivefolds respectively. From this point, it is clear that appropriate ErbB receptor levels and PKC inhibition are necessary to enhance the effect of the CM in inducing the neuronal-like differentiation of PC12 cells. In summary, we demonstrated the involvement of ErbB receptors in the regulation of neurite elongation and sodium current induction in PC12 cells and propose that these processes could be initiated by ErbB receptors followed by a fine regulation of PKC signaling. These findings might implicate a novel interplay between ErbB receptors and PKC in the regulation of these molecular mechanisms.

Vertebral hemangioma: "Cold" vertebrae on bone scintigraphy and fluordeoxy-glucose positron emission tomography-computed tomography

Bone hemangiomas are benign and infrequent lesions. At Tc-99m bone scintigraphy they show variable degrees of radiotracer uptake and even absence of it. At fluordeoxy-glucose (FDG) Positron Emission Tomography-Computed Tomography (PET/CT), hemangioma is one of the causes of “cold” vertebrae, apart from postexternal radiotherapy. We present a woman diagnosed of breast carcinoma, with a photopenic defect at a thoracic vertebrae at Tc-99m bone scan. In order to rule out bone lytic metastasis, a FDG PET/CT was performed showing a “cold” vertebrae too. Findings were highly suggestive of vertebral hemangioma, that was confirmed by magnetic resonance imaging.

The usefulness of densitometry as a method of assessing the nutritional status of athletes. Comparison with body mass index

The body mass index (BMI) is used to assess nutritional status. The result in athletes may be overestimated due to increase in muscle mass.

OBJECTIVE

To assess the usefulness of fat mass index (FMI) and lean mass index (LMI) determination as indicators of nutritional status and to compare the results with BMI.

MATERIAL AND METHODS

We studied 28 amateur rugby players, male. After being subjected to whole body densitometry by dual X-ray absorptiometry, we determined fat and lean body mass together with other parameters. FMI (fat in kg/height in meters(2)), LMI (lean in kg/height in meters(2)) and appendicular muscle mass index (AMMI, arms and legs musculature in kg/height in meters(2)) were calculated.

RESULTS

Using BMI, 18 players were overweight and 4 obese type I. Considering FMI, 7 of them had normal values and high LMI and AMMI, one of them changed from overweight to obese and another one from obese to overweight. Of the 6 players with normal BMI, one of them showed fat excess and another one fat defect. The results changed the assessment of nutritional status in 39% of players.

CONCLUSIONS

Although BMI is an appropriate parameter in general population for the assessment of nutritional status, in athletes should be taken into account fat and muscle body percentage and their corresponding indexes. The whole body densitometry appears to be a simple and reliable technique for this purpose.

Lymphoscintigraphy for differential diagnosis of peripheral edema: diagnostic yield of different scintigraphic patterns

Edema of the limbs is a common reason for medical consultation, for which the lymphoscintigraphy is considered to be a reliable method for its differential diagnosis.

OBJECTIVE

To evaluate the usefulness of radionuclide studies in the differential diagnosis of edema, and the diagnostic yield of different scintigraphic patterns.

MATERIAL AND METHODS

A total of 61 patients, mean age 43 years, referred to our Department in the last three years for suspected lymphoedema, were considered. One patient was discarded due to lack of diagnosis, 56 had lower limb edema and 4 upper limb edema. After intradermal injection of two doses of (99m)Tc-nanocolloid, scintigraphic scans were made at 30 and 120minutes. The final diagnosis was based on imaging tests, clinical course, and response to treatment. We calculated the parameters of the diagnostic yield of four different scintigraphic patterns (presence of dermal backflow, asymmetry-alteration in inguinal/axillary nodes, presence of collateral pathways, and visualization of intermediate lymph nodes), considering them individually and jointly.

RESULTS

The best diagnostic yield was achieved by considering dermal backflow and asymmetry in inguinal/axillary nodes (accuracy 88.9%, specificity 96.4%, PPV 95.5%). Evaluation of intermediate lymph nodes and presence of collateral pathways contributed little to the diagnostic yield, showing poor sensitivity and high false positive rates.

CONCLUSION

The lymphoscintigraphy had high diagnostic yield, allowing early treatment of lymphœdema. The dermal backflow and asymmetry in inguinal/axillary nodes had the greatest diagnostic accuracy. Evaluation of intermediate lymph nodes and visualization of collateral pathways contributed little to improving the diagnosis.

Dynamical coupling between gradients and transport in fusion plasmas

The dynamical coupling between density gradients and particle transport has been investigated using similar experimental tools in the plasma boundary of different tokamak (JET, ISTTOK) and stellarator (TJ-II) devices, showing that the size of turbulent events is minimum in the proximity of the most probable density gradient. Experimental results were found to be consistent with results from two very different models of plasma turbulence and transport. The present findings, common to several plasma devices, suggest the importance of self-regulation mechanisms between plasma transport and gradients in fusion devices.

Study of biodiesel production from animal fats with high free fatty acid content

The aim of this work was to obtain biodiesel from animal fats, an inedible feedstock. Three different types of fats were used to produce biodiesel; their main characteristic was high free fatty acid content. Animal fats were transesterified with acid catalyst and basic catalyst with and without pre-esterification. Biodiesel of 89.0 wt.% ester content was obtained by acid-transesterification (9 wt.%H2SO4, 6:1 methanol:fats molar ratio, 60 °C, 48 h). Pre-esterification conditions were studied for different fats and acid catalysts: 0.5 wt.%H2SO4 or 1.0 wt.%p-TsOH, 6:1 methanol:fats molar ratio, 65 °C and 4 h made it possible to obtain fats with acid value less than 0.5% FFA. Pre-treatment was effective for fats with different FFA content. Alkali transesterification of esterified fats resulted in a product with 97.3 wt.% ester content. Biodiesel quality was evaluated and most of properties were well within EN 14214.

Effect of using reporting guidelines during peer review on quality of final manuscripts submitted to a biomedical journal: masked randomised trial

OBJECTIVE

To investigate the effect of an additional review based on reporting guidelines such as STROBE and CONSORT on quality of manuscripts.

DESIGN

Masked randomised trial. Population Original research manuscripts submitted to the Medicina Clínica journal from May 2008 to April 2009 and considered suitable for publication.

INTERVENTION

CONTROL GROUP

conventional peer reviews alone. Intervention group: conventional review plus an additional review looking for missing items from reporting guidelines. Outcomes Manuscript quality, assessed with a 5 point Likert scale (primary: overall quality; secondary: average quality of specific items in paper). Main analysis compared groups as allocated, after adjustment for baseline factors (analysis of covariance); sensitivity analysis compared groups as reviewed. Adherence to reviewer suggestions assessed with Likert scale.

RESULTS

Of 126 consecutive papers receiving conventional review, 34 were not suitable for publication. The remaining 92 papers were allocated to receive conventional reviews alone (n=41) or additional reviews (n=51). Four papers assigned to the conventional review group deviated from protocol; they received an additional review based on reporting guidelines. We saw an improvement in manuscript quality in favour of the additional review group (comparison as allocated, 0.25, 95% confidence interval -0.05 to 0.54; as reviewed, 0.33, 0.03 to 0.63). More papers with additional reviews than with conventional reviews alone improved from baseline (22 (43%) v eight (20%), difference 23.6% (3.2% to 44.0%), number needed to treat 4.2 (from 2.3 to 31.2), relative risk 2.21 (1.10 to 4.44)). Authors in the additional review group adhered more to suggestions from conventional reviews than to those from additional reviews (average increase 0.43 Likert points (0.19 to 0.67)).

CONCLUSIONS

Additional reviews based on reporting guidelines improve manuscript quality, although the observed effect was smaller than hypothesised and not definitively demonstrated. Authors adhere more to suggestions from conventional reviews than to those from additional reviews, showing difficulties in adhering to high methodological standards at the latest research phases. To boost paper quality and impact, authors should be aware of future requirements of reporting guidelines at the very beginning of their study. Trial registration and protocol Although registries do not include trials of peer review, the protocol design was submitted to sponsored research projects (Instituto de Salud Carlos III, PI081903).

The effects of cause of death classification on prognostic assessment of patients with pulmonary embolism

BACKGROUND

Although previous studies have provided evidence that the majority of deaths following an acute pulmonary embolism (PE) directly relate to the PE, more recent registries and cohort studies suggest otherwise.

METHODS

We assessed the cause of death during the first 30 days after the diagnosis of acute symptomatic PE in a consecutive series of patients. We also assessed the prognostic characteristics of the simplified Pulmonary Embolism Severity Index (sPESI) and cardiac troponin I (cTnI) obtained at the time of PE diagnosis.

RESULTS

During the first 30 days after diagnosis, 127 of the 1291 patients died (9.8%; 95% confidence interval [CI], 8.2-11.5). Sixty patients (4.6%; 95% CI, 3.5-5.8) died from definite or possible PE, and 67 (5.2%; 95% CI, 4.0-6.4) died from other causes (cancer 25, infection 18, hemorrhage 7, heart failure 7, chronic obstructive pulmonary disease 5, renal failure 1, seizures 1, unknown 3). The sPESI predicted all-cause (odds ratio [OR], 5.97; 95% CI, 1.74-20.54; P < 0.01) and PE-associated mortality (OR, 8.79; 95% CI, 1.12-68.79; P = 0.04). cTnI only predicted PE-associated mortality (adjusted OR, 2.39; 95% CI, 1.25-4.57; P < 0.01). For all-cause mortality, the sPESI low-risk strata had a negative predictive value of 98.8% (95% CI, 97.4-100) in comparison with 91.3% (95% CI, 88.9-93.6) for the cTnI.

CONCLUSIONS

Within the first 30 days after the diagnosis of acute symptomatic PE, death due to PE and death due to other causes occur in a similar proportion of patients. As cTnI only predicted PE-associated mortality, low-risk sPESI had a higher negative predictive value for all-cause mortality compared with cTnI.

Multiple sclerosis prevalence in Malaga, Southern Spain estimated by the capture–recapture method

Background: Although not definitively proven, there is commonly accepted to be a latitudinal gradient in the distribution of multiple sclerosis (MS), which is more frequent in temperate zones. The European Mediterranean countries are situated in a zone of median frequency, although ever increasing figures have been noted in the last decades.

Objective: The objective of this study was to assess the current prevalence rate of MS in the province of Malaga, Southern Spain.

Methods: The capture–recapture method (CRM) uses independent sources of data and permits the number of non-registered cases of a given disease to be estimated, and by doing so, to avoid ascertainment bias.

Results: Use of this method showed the estimated prevalence rate of MS in the province of Malaga, Southern Spain, to be 125/105 (95% confidence interval: 102/105–169/105), higher than the figures published previously.

Conclusions: Although we recognize that these data need to be confirmed in further studies and in other areas of the country using a similar method, we believe this study is the first to find such high figure of prevalence, being very similar to the figures reported in recent years in other southern European countries.

SPECT-CT with 67Ga-citrate in the management of spondylodiscitis

Spondylodiscitis affects a small proportion of all patients with locomotor system infections, however its early diagnosis is important due to its potential morbidity. Magnetic resonance imaging is the diagnostic method of choice. Nonetheless, it has certain limitations and is not suitable for all patients. The conventional scintigraphic studies for evaluating spondylodiscitis are those performed with (99m)Tc-HDP and (67)Ga-citrate. However, their poor image resolution is a disadvantage of these techniques. The use of hybrid Single Photon Emission Computed Tomography-Computed Tomography (SPECT-CT) improves detection of the disease by combining functional and anatomical images. We present 9 patients with suspicion of spondylodiscitis who underwent sequential bone scintigraphy with (99m)Tc-HDP and SPECT-CT with (67)Ga-citrate, with positive findings confirmed by clinical monitoring for at least 6 months.